coelacanth

The word Coelacanth is an adaptation of the Modern Latin {{Lang|la|Cœlacanthus}} ('hollow spine'), from the Ancient Greek {{lang|grc|κοῖλ-ος}} ({{transliteration|grc|koilos}}, 'hollow') and {{lang|grc|ἄκανθ-α}} ({{transliteration|grc|akantha}}, 'spine'),{{cite web|title = The Coelancanth|url = http://www.actforlibraries.org/the-coelancanth/|website = actforlibraries.org|access-date = 2015-10-30}} referring to the hollow caudal fin rays of the first fossil specimen described and named by Louis Agassiz in 1839, belonging to the genus Coelacanthus.{{rp|1}} The genus name Latimeria commemorates Marjorie Courtenay-Latimer, who discovered the first specimen.{{cite web|title = Smithsonian Institution – The Coelacanth: More Living than Fossil|url = http://vertebrates.si.edu/fishes/coelacanth/coelacanth_wider.html|website = vertebrates.si.edu|access-date = 2015-10-30}}

File:Coelacanthus granulatus.JPG, the first described coelacanth, named by Louis Agassiz in 1839]]

The earliest fossils of coelacanths were discovered in the 19th century. Coelacanths, which are related to lungfishes and tetrapods, were believed to have become extinct at the end of the Cretaceous period.{{cite web|title = Coelacanth – Deep Sea Creatures on Sea and Sky|url = http://www.seasky.org/deep-sea/coelacanth.html|website = seasky.org|access-date = 2015-10-27}} More closely related to tetrapods than to the ray-finned fish, coelacanths were considered transitional species between fish and tetrapods.{{Cite journal |last=Meyer |first=Axel |title=Molecular evidence on the origin of tetrapods and the relationships of the coelacanth |journal=Trends in Ecology & Evolution |volume=10 |issue=3 |pages=111–116 |doi=10.1016/s0169-5347(00)89004-7 |pmid=21236972 |year=1995 |bibcode=1995TEcoE..10..111M |url=http://nbn-resolving.de/urn:nbn:de:bsz:352-opus-36291 |type=Submitted manuscript}} On 22 December 1938, the first Latimeria specimen was found off the east coast of South Africa, off the Chalumna River (now Tyolomnqa).{{Cite web |title=Marjorie Courtenay-Latimer |url=https://www.lindahall.org/about/news/scientist-of-the-day/marjorie-courtenay-latimer/ |date=24 February 2020|access-date=2024-12-20 |website=The Linda Hall Library |language=en-US}}{{Cite journal |last=Smith |first=J. L. B. |date=March 1939 |title=A Living Fish of Mesozoic Type |url=https://www.nature.com/articles/143455a0 |journal=Nature |language=en |volume=143 |issue=3620 |pages=455–456 |doi=10.1038/143455a0 |bibcode=1939Natur.143..455S |issn=0028-0836}} Museum curator Marjorie Courtenay-Latimer discovered the fish among the catch of a local fisherman. Courtenay-Latimer contacted a Rhodes University ichthyologist, J. L. B. Smith, sending him drawings of the fish, and he confirmed the fish's importance with a famous cable: "Most Important Preserve Skeleton and Gills = Fish Described."

Its discovery 66 million years after its supposed extinction makes the coelacanth the best-known example of a Lazarus taxon, an evolutionary line that seems to have disappeared from the fossil record only to reappear much later. Since 1938, West Indian Ocean coelacanth have been found in the Comoros, Kenya, Tanzania, Mozambique, Madagascar, in iSimangaliso Wetland Park, and off the South Coast of Kwazulu-Natal in South Africa.{{cite journal|last1=Venter|first1=P.|last2=Timm|first2=P.|last3=Gunn|first3=G.|last4=le Roux|first4=E.|last5=Serfontein|first5=C.|year=2000|title=Discovery of a viable population of coelacanths (Latimeria chalumnae Smith, 1939) at Sodwana Bay, South Africa|journal=South African Journal of Science|volume=96|issue=11/12|pages=567–568}}{{cite journal|url=https://www.sajs.co.za/article/view/7806/9870 |title=Live coelacanth discovered off the KwaZulu-Natal South Coast, South Africa |journal=South African Journal of Science |volume=116 |issue=3/4 March/April 2020 |first1=Michael D. |last1=Fraser |first2=Bruce A.S. |last2=Henderson |first3=Pieter B. |last3=Carstens |first4=Alan D. |last4=Fraser |first5=Benjamin S. |last5=Henderson |first6=Marc D. |last6=Dukes |first7=Michael N. |last7=Bruton |doi=10.17159/sajs.2020/7806 |date=26 March 2020 |doi-access=free }}

The Comoro Islands specimen was discovered in December 1952.{{Cite news|url=https://www.newspapers.com/clip/11755015/prehistoric_fish_offers_rare_glimpse_of/|title=Prehistoric fish offers rare glimpse of hidden sea life – Coelacanth (1953)|date=1953-02-23|work=Abilene Reporter-News|access-date=2017-06-18|page=25}} Between 1938 and 1975, 84 specimens were caught and recorded.{{Cite news|url=https://www.newspapers.com/clip/11755368/70millionyearold_fish_dissected/|title=70-million-year-old fish dissected – Coaelacanth (1975)|date=1975-05-28|work=Redlands Daily Facts|access-date=2017-06-18|page=6}}

The second extant species, the Indonesian coelacanth, was described from Manado, North Sulawesi, Indonesia, in 1999 by Pouyaud et al.{{cite journal |doi=10.1016/S0764-4469(99)80061-4 |title=Une nouvelle espèce de cœlacanthe. Preuves génétiques et morphologiques |trans-title=A new species of coelacanth. Genetic and morphologic proof |language=fr |year=1999 |last1=Pouyaud |first1=Laurent |last2=Wirjoatmodjo |first2=Soetikno |last3=Rachmatika |first3=Ike |last4=Tjakrawidjaja |first4=Agus |last5=Hadiaty |first5=Renny |last6=Hadie |first6=Wartono |journal=Comptes Rendus de l'Académie des Sciences |volume=322 |issue=4 |pages=261–7 |bibcode=1999CRASG.322..261P |pmid=10216801}} based on a specimen discovered by Mark V. Erdmann in 1998{{cite journal |doi=10.1038/26376 |year=1998 |last1=Erdmann |first1=Mark V. |last2=Caldwell |first2=Roy L. |last3=Moosa |first3=M. Kasim |journal=Nature |volume=395 |issue=6700 |page=335 |bibcode=1998Natur.395..335E |title=Indonesian 'king of the sea' discovered|s2cid=204997216 |doi-access=free }} and deposited at the Indonesian Institute of Sciences (LIPI).{{cite journal |url=https://www.science.org/content/article/dispute-over-legendary-fish |title= Dispute Over a Legendary Fish|first= Constance |last=Holden|date=30 March 1999 |journal=Science |volume= 284|issue= 5411|pages= 22–3|doi= 10.1126/science.284.5411.22b|pmid= 10215525|s2cid= 5441807|url-access= subscription}} Erdmann and his wife Arnaz Mehta first encountered a specimen at a local market in September 1997, but took only a few photographs of the first specimen of this species before it was sold. After confirming that it was a unique discovery, Erdmann returned to Sulawesi in November 1997 to interview fishermen and look for further examples. A second specimen was caught by a fisherman in July 1998 and was then handed to Erdmann.{{cite journal |title=Coelacanth discovery in Indonesia |first=Henry |last=Gee |date= 1 October 1998 | journal=Nature | doi=10.1038/news981001-1 }}{{cite web |url=http://www.ucmp.berkeley.edu/vertebrates/coelacanth/coelacanth1.html |title=The Discovery |publisher=University of California Museum of Paleontology }}

File:Latimeria chalumnae replica.jpg]]

File:Latimeria menadoensis.jpg, Japan]]

Latimeria chalumnae and L. menadoensis are the only two known living coelacanth species.{{rp|1,6}}{{cite book |last1=Nelson |first1=Joseph S. |title=Fishes of the World |location=Hoboken, New Jersey |publisher=John Wiley |year=2006 |isbn=978-0-471-75644-6 |page=461}} Coelacanths are large, plump, lobe-finned fish that can grow to more than {{Convert|2|m|ft|abbr=on}} and weigh around {{Convert|90|kg|lb|abbr=on}}.{{cite web|title = Coelacanths, Coelacanth Pictures, Coelacanth Facts – National Geographic|url = http://animals.nationalgeographic.com/animals/fish/coelacanth/|archive-url = https://web.archive.org/web/20100114080556/http://animals.nationalgeographic.com/animals/fish/coelacanth|url-status = dead|archive-date = 14 January 2010|website = National Geographic|access-date = 2015-10-28|date = 2011-05-10}} They are estimated to live up to 100 years, based on analysis of annual growth marks on scales, and reach maturity around the age of 55;{{cite web |url=https://www.eurekalert.org/pub_releases/2021-06/cp-cml061021.php |title=Coelacanths may live nearly a century, five times longer than researchers expected |work=Eurekalert |date=17 June 2021 |access-date=17 June 2021}} the oldest known specimen was 84 years old at the time of its capture in 1960.{{cite journal |last1=Mahé |first1=Kélig |last2=Ernande |first2=Bruno |last3=Herbin |first3=Marc |title=New scale analyses reveal centenarian African coelacanths |journal=Current Biology |publisher=Cell Press |date=17 June 2021 |volume=31 |issue=16 |pages=3621–3628.e4 |doi=10.1016/j.cub.2021.05.054 |pmid=34143958 |issn=0960-9822|doi-access=free |bibcode=2021CBio...31E3621M }}

Even though their estimated lifetime is similar to humans, gestation can last 5 years, which is 1.5 years more than the deep-sea frilled shark, the previous record holder.{{cite magazine |url=https://www.economist.com/science-and-technology/2021/06/19/coelacanths-live-for-as-long-as-people |title=Coelacanths live for as long as people |magazine=The Economist |date=19 June 2021 |access-date=19 August 2021}}

They are nocturnal piscivorous drift-hunters.{{cite journal |bibcode=1987Natur.329..331F |title=Locomotion of the coelacanth Latimeria chalumnae in its natural environment |last1=Fricke |first1=Hans |last2=Reinicke |first2=Olaf |last3=Hofer |first3=Heribert |last4=Nachtigall |first4=Werner |volume=329 |year=1987 |pages=331–3 |journal=Nature |doi=10.1038/329331a0 |issue=6137|s2cid=4353395 }}

The body is covered in ctenoid elasmoid scales that act as armor.{{Cite journal |last=Sherman |first=Vincent R. |title=A comparative study of piscine defense: The scales of Arapaima gigas, Latimeria chalumnae and Atractosteus spatula |journal=Journal of the Mechanical Behavior of Biomedical Materials |volume=73 |pages=1–16 |year=2016 |doi=10.1016/j.jmbbm.2016.10.001 |pmid=27816416 }} Coelacanths have eight fins – two dorsal fins, two pectoral fins, two pelvic fins, one anal fin and one caudal fin. The tail is very nearly equally proportioned and is split by a terminal tuft of fin rays that make up its caudal lobe. The eyes of the coelacanth are very large, while the mouth is very small.{{citation needed|date=December 2021|reason=Contradicted by most every picture here, esp. the one adjacent to this text, dropped here 10 years ago (Jhende34) then editor disappeared, can't find any support for this statement "very small"}} The eye is acclimatized to seeing in poor light by rods that absorb mostly short wavelengths. Coelacanth vision has evolved to a mainly blue-shifted color capacity.{{cite journal |bibcode=1999PNAS...96.6279Y |title=Adaptive Evolution of Color Vision of the Comoran Coelacanth (Latimeria chalumnae) |last1=Yokoyama |first1=Shozo |last2=Zhang |first2=Huan |last3=Radlwimmer |first3=F. Bernhard |last4=Blow |first4=Nathan S. |volume=96 |year=1999 |pages=6279–84 |journal=Proceedings of the National Academy of Sciences of the United States of America |doi=10.1073/pnas.96.11.6279 |pmid=10339578 |issue=11 |pmc=26872 |jstor=47861|doi-access=free }} Pseudomaxillary folds surround the mouth and replace the maxilla, a structure absent in coelacanths. Two nostrils, along with four other external openings, appear between the premaxilla and lateral rostral bones. The nasal sacs resemble those of many other fish and do not contain an internal nostril. The coelacanth's rostral organ, contained within the ethmoid region of the braincase, has three unguarded openings into the environment and is used as a part of the coelacanth's laterosensory system.{{rp|14–16, 19}} The coelacanth's auditory reception is mediated by its inner ear, which is very similar to that of tetrapods and is classified as being a basilar papilla.{{cite journal |bibcode=1987Natur.327..153F |title=Inner ear of the coelacanth fish Latimeria has tetrapod affinities |last1=Fritzsch |first1=B. |volume=327 |year=1987 |pages=153–4 |journal=Nature |doi=10.1038/327153a0 |pmid=22567677 |issue=6118|s2cid=4307982 }}

Coelacanths are a part of the clade Sarcopterygii, or the lobe-finned fishes. They share membership in this clade with lungfish and tetrapods. Externally, several characteristics distinguish coelacanths from other lobe-finned fish. They possess a three-lobed caudal fin, also called a trilobate fin or a diphycercal tail. A secondary tail extending past the primary tail separates the upper and lower halves of the coelacanth. Ctenoid elasmoid scales act as thick armor to protect the coelacanth's exterior. Several internal traits also aid in differentiating coelacanths from other lobe-finned fish. At the back of the skull, the coelacanth possesses a hinge, the intracranial joint, which allows it to open its mouth extremely wide. Coelacanths also retain an oil-filled notochord, a hollow, pressurized tube which is replaced by a vertebral column early in embryonic development in most other vertebrates.{{Cite web|url=http://www.scienceinafrica.co.za/2002/february/coela.htm|archive-url=https://web.archive.org/web/20130921055458/http://www.scienceinafrica.co.za/2002/february/coela.htm|url-status=dead|title=What do we know about the coelacanths – Science in Africa|archive-date=21 September 2013}} The coelacanth's heart is shaped differently from that of most modern fish, with its chambers arranged in a straight tube. The coelacanth's braincase is 98.5% filled with fat; only 1.5% of the braincase contains brain tissue. The cheeks of the coelacanth are unique because the opercular bone is very small and holds a large soft-tissue opercular flap. A spiracular chamber is present, but the spiracle is closed and never opens during development.{{Cite book|url=https://books.google.com/books?id=4j9AKGsQ1msC&q=%22spiracular+chamber+is+closed+in+coelacanths%22&pg=PA391|title=Gaining Ground, Second Edition: The Origin and Evolution of Tetrapods|first=Jennifer A.|last=Clack|date=27 June 2012|page=391|publisher=Indiana University Press|isbn=978-0-253-00537-3}}{{rp|15}}{{cite web |title=The Coelacanth – a Morphological Mixed Bag |publisher=ReefQuest Centre for Shark Research |url=http://www.elasmo-research.org/education/classification/coelacanth.htm}} Also unique to extant coelacanths is the presence of a "fatty lung" or a fat-filled single-lobed vestigial lung, homologous to other fishes' swim bladders. The parallel development of a fatty organ for buoyancy control suggests a unique specialization for deep-water habitats. There are small and hard but flexible plates around the vestigial lung in adult specimens, though not around the fatty organ. The plates most likely had a regulation function for the volume of the lung.{{cite journal |doi=10.1111/j.1475-4983.2010.01015.x |title=The histological structure of the calcified lung of the fossil coelacanth Axelrodichthys araripensis (Actinistia: Mawsoniidae) |year=2010 |last1=Brito |first1=Paulo M. |last2=Meunier |first2=François J. |last3=Clément |first3=Gael |last4=Geffard-Kuriyama links|first4=Didier |journal=Palaeontology |volume=53 |issue=6 |pages=1281–90|bibcode=2010Palgy..53.1281B |doi-access=free }} Due to the size of the fatty organ, researchers assume that it is responsible for the kidney's unusual relocation. The two kidneys, which are fused into one,{{Cite book|url=https://books.google.com/books?id=hPEJAwAAQBAJ&q=%22amounts.+The+paired+kidneys+are+fused%2C+%22&pg=PA92|title=From fish to philosopher|first=H. W.|last=Smith|date=24 October 2018|publisher=Рипол Классик|isbn=9785873926930|page=92}} are located ventrally within the abdominal cavity, posterior to the cloaca.{{Cite book|url=https://books.google.com/books?id=wHZ6WwqbrmkC&q=%22amongst+vertebrates+in+being+located+ventrally%22&pg=PA26|title=History of the Coelacanth Fishes|first=Peter|last=Forey|date=30 November 1997|publisher=Springer Science & Business Media|isbn=978-0-412-78480-4|page=26}}

File:Latimeria chalumnae.jpg (Anjouan, Comoro Islands)]]

File:Pectoral fin Latimeria chalumnae.jpg of a West Indian Ocean coelacanth]]

In 2013, a research group published the genome sequence of the coelacanth in the scientific journal Nature.{{cite journal | title = The African coelacanth genome provides insights into tetrapod evolution | journal = Nature | date = 18 April 2013 | doi = 10.1038/nature12027 | last1 = Amemiya | first1 = Chris T. | last2 = Alföldi | first2 = Jessica | last3 = Lee | first3 = Alison P. | last4 = Fan | first4 = Shaohua | last5 = Philippe | first5 = Hervé | last6 = MacCallum | first6 = Iain | last7 = Braasch | first7 = Ingo | last8 = Manousaki | first8 = Tereza | last9 = Schneider | first9 = Igor | volume = 496 | issue = 7445 | pages = 311–6 | pmid = 23598338 | pmc = 3633110|bibcode = 2013Natur.496..311A | display-authors = 9 | last10 = Rohner | first10 = Nicolas | last11 = Organ | first11 = Chris | last12 = Chalopin | first12 = Domitille | last13 = Smith | first13 = Jeramiah J. | last14 = Robinson | first14 = Mark | last15 = Dorrington | first15 = Rosemary A. | last16 = Gerdol | first16 = Marco | last17 = Aken | first17 = Bronwen | last18 = Biscotti | first18 = Maria Assunta | last19 = Barucca | first19 = Marco | last20 = Baurain | first20 = Denis | last21 = Berlin | first21 = Aaron M. | last22 = Blatch | first22 = Gregory L. | last23 = Buonocore | first23 = Francesco | last24 = Burmester | first24 = Thorsten | last25 = Campbell | first25 = Michael S. | last26 = Canapa | first26 = Adriana | last27 = Cannon | first27 = John P. | last28 = Christoffels | first28 = Alan | last29 = De Moro | first29 = Gianluca | last30 = Edkins | first30 = Adrienne L. }}

Due to their lobed fins and other features, it was once hypothesized that the coelacanth might be the youngest diverging non-tetrapod sarcopterygian.{{cite journal |doi=10.1002/jmor.1051900418|title=Lungfish neural characters and their bearing on sarcopterygian phylogeny|journal=Journal of Morphology|volume=190|pages=277–297|year=1986|last1=Northcutt|first1=R. Glenn|hdl=2027.42/50281|s2cid=35473487|url=https://deepblue.lib.umich.edu/bitstream/2027.42/50281/1/1051900418_ftp.pdf|hdl-access=free}} But after sequencing the full genome of the coelacanth, it was discovered that the lungfish instead is more closely related to tetrapods. Coelacanths and rhipidistians (the concestor of lungfish and tetrapods) had already diverged from each other before the lungfish made the transition to land.{{cite web|url=http://www.smithsonianmag.com/science-nature/dna-sequencing-reveals-that-coelacanths-werent-the-missing-link-between-sea-and-land-25025860/?no-ist|title=DNA Sequencing Reveals that Coelacanths Weren't the Missing Link Between Sea and Land|first=Joseph|last=Stromberg|publisher=Smithsonian Magazine}}

Another important discovery made from the genome sequencing is that the coelacanths are still evolving today. While phenotypic similarity between extant and extinct coelacanths suggests there is limited evolutionary pressure on these organisms to undergo morphological divergence, they are undergoing measurable genetic divergence. Despite prior studies showing that protein coding regions are undergoing evolution at a substitution rate much lower than other sarcopterygians (consistent with phenotypic stasis observed between extant and fossil members of the taxa), the non-coding regions subject to higher transposable element activity show marked divergence even between the two extant coelacanth species. This has been facilitated in part by a coelacanth-specific endogenous retrovirus of the Epsilon retrovirus family.{{Cite journal|doi=10.1371/journal.pone.0114382|doi-access=free|title=Interspecies Insertion Polymorphism Analysis Reveals Recent Activity of Transposable Elements in Extant Coelacanths|year=2014|last1=Naville|first1=Magali|last2=Chalopin|first2=Domitille|last3=Volff|first3=Jean-Nicolas|journal=PLOS ONE|volume=9|issue=12|pages=e114382|pmid=25470617|pmc=4255032|bibcode=2014PLoSO...9k4382N}}File:Fishapods.svg vertebrate speciation, descendants of pelagic lobe-finned fish—like Eusthenopteron—exhibited a sequence of adaptations: Panderichthys, suited to muddy shallows; Tiktaalik with limb-like fins that could take it up onto land; and Early tetrapods in weed-filled swamps, such as Acanthostega which had feet with eight digits and Ichthyostega with limbs. Descendants also included pelagic lobe-finned fish such as the coelacanth species.]]

File:Libys sp.jpg (Latimeriidae) from the Upper Jurassic of Germany]]

File:Mawsonia scaling.png compared to a human]]

File:Allenypterus montanus (Restoration).jpg from the Carboniferous of North America]]

Coelacanths are members of the class Actinistia, with many researchers considering the term "coelacanth" to cover all members of Actinistia.{{Cite journal |last1=Toriño |first1=Pablo |last2=Soto |first2=Matías |last3=Perea |first3=Daniel |date=2021-02-25 |title=A comprehensive phylogenetic analysis of coelacanth fishes (Sarcopterygii, Actinistia) with comments on the composition of the Mawsoniidae and Latimeriidae: evaluating old and new methodological challenges and constraints |url=https://www.researchgate.net/publication/349631865 |journal=Historical Biology |volume=33 |issue=12 |pages=3423–3443 |bibcode=2021HBio...33.3423T |doi=10.1080/08912963.2020.1867982 |issn=0891-2963 |s2cid=233942585}} The order Coelacanthiformes has been used for a subgroup of actinistians, containing the modern coelacanths, as well as well as other extinct closely related actinistians spanning from the Permian onwards.{{Cite journal |last1=Arratia |first1=Gloria |last2=Schultze |first2=Hans-Peter |date=2015-09-03 |title=A new fossil actinistian from the Early Jurassic of Chile and its bearing on the phylogeny of Actinistia |url=http://www.tandfonline.com/doi/full/10.1080/02724634.2015.983524 |journal=Journal of Vertebrate Paleontology |language=en |volume=35 |issue=5 |pages=e983524 |doi=10.1080/02724634.2015.983524 |bibcode=2015JVPal..35E3524A |issn=0272-4634|url-access=subscription }}{{Cite journal |last1=Ferrante |first1=Christophe |last2=Cavin |first2=Lionel |date=2025-06-06 |editor-last=Carnevale |editor-first=Giorgio |title=A deep dive into the coelacanth phylogeny |journal=PLOS ONE |language=en |volume=20 |issue=6 |pages=e0320214 |doi=10.1371/journal.pone.0320214 |doi-access=free |pmid=40478838 |issn=1932-6203}} According to the fossil record, the divergence of coelacanths, lungfish, and tetrapods is thought to have occurred during the Silurian.{{Cite journal|last1=Lu|first1=Jing|last2=Giles|first2=Sam|last3=Friedman|first3=Matt|last4=Zhu|first4=Min|date=2017-12-05|title=A new stem sarcopterygian illuminates patterns of character evolution in early bony fishes|journal=Nature Communications|language=en|volume=8|issue=1|pages=1932|doi=10.1038/s41467-017-01801-z|pmid=29203766|issn=2041-1723|pmc=5715141|bibcode=2017NatCo...8.1932L}} Over 100 fossil species of coelacanth have been described. The oldest identified coelacanth fossils are around 420–410 million years old, dating to the Pragian stage of the early Devonian. These include Eoactinistia from Australia, known only from a fragmentary jaw, as well as Euporosteus yunnanensis from China, known from a partial skull that indicates it to be the earliest anatomically modern coelacanth.{{Cite journal |last1=Zhu |first1=Min |last2=Yu |first2=Xiaobo |last3=Lu |first3=Jing |last4=Qiao |first4=Tuo |last5=Zhao |first5=Wenjin |last6=Jia |first6=Liantao |date=2012-04-10 |title=Earliest known coelacanth skull extends the range of anatomically modern coelacanths to the Early Devonian |url=https://www.nature.com/articles/ncomms1764 |journal=Nature Communications |language=en |volume=3 |issue=1 |pages=772 |doi=10.1038/ncomms1764 |pmid=22491320 |bibcode=2012NatCo...3..772Z |issn=2041-1723}} Some authors have also suggested that the slightly older onychodont Styloichthys may also be an early coelacanth.{{cite journal|last=Friedman|first=Matt|date=10 August 2007|title=Styloichthys as the oldest coelacanth: implications for early osteichthyan interrelationships |url=https://www.tandfonline.com/doi/abs/10.1017/S1477201907002052 |journal=Journal of Systematic Palaeontology|volume=5|issue=3|pages=289–343|doi=10.1017/S1477201907002052|bibcode=2007JSPal...5..289F |s2cid=83712134|access-date=2007-12-28|url-access=subscription}}

Coelacanths were never a diverse group in comparison to other groups of fish, and reached a peak diversity during the Early Triassic (252–247 million years ago), coinciding with a burst of diversification between the Late Permian and Middle Triassic. Most Mesozoic coelacanths belong to the suborder Latimerioidei, which contains two major subdivisions, the marine Latimeriidae, which contains modern coelacanths, as well as the extinct Mawsoniidae, which were native to brackish, freshwater as well as marine environments.{{Cite journal|last1=Cavin|first1=Lionel|last2=Cupello|first2=Camila|last3=Yabumoto|first3=Yoshitaka|last4=Léo|first4=Fragoso|last5=Deersi|first5=Uthumporn|last6=Brito|first6=Paul M.|date=2019|title=Phylogeny and evolutionary history of mawsoniid coelacanths|url=http://www.kmnh.jp/wp-content/uploads/2019/05/A17-3-Cavin.pdf|journal=Bulletin of the Kitakyushu Museum of Natural History and Human History, Series A|volume=17|pages=3–13}}

Paleozoic coelacanths are generally small (~{{Cvt|30–40|cm|disp=or}} in length), while Mesozoic forms were larger. Several specimens belonging to the Jurassic and Cretaceous mawsoniid coelacanth genera Trachymetopon and Mawsonia likely reached or exceeded {{Convert|5|m|ft|abbr=off}} in length, making them amongst the largest known fishes of the Mesozoic, and amongst the largest bony fishes of all time.{{Cite journal|last1=Cavin|first1=Lionel|last2=Piuz|first2=André|last3=Ferrante|first3=Christophe|last4=Guinot|first4=Guillaume|date=2021-06-03|title=Giant Mesozoic coelacanths (Osteichthyes, Actinistia) reveal high body size disparity decoupled from taxic diversity|journal=Scientific Reports|language=en|volume=11|issue=1|pages=11812|doi=10.1038/s41598-021-90962-5|pmid=34083600|issn=2045-2322|pmc=8175595|bibcode=2021NatSR..1111812C}}

The most recent fossil latimeriid is Megalocoelacanthus dobiei, whose disarticulated remains are found in late Santonian to middle Campanian, and possibly earliest Maastrichtian-aged marine strata of the Eastern and Central United States,{{cite journal|last1=Schwimmer|first1=D.R.|author2=Stewart, J.D.|author3=Williams, G.D.|title=Giant fossil coelacanths of the Late Cretaceous in the eastern United States|journal=Geology|date=1994|volume=2|issue=6|pages=503–506|doi=10.1130/0091-7613(1994)022<0503:GFCOTL>2.3.CO;2|bibcode=1994Geo....22..503S}}{{cite journal|author1=Gottfried, Michael D. |author2=Rogers, Raymond R. |author3=Rogers, K. Curry |title=First record of Late Cretaceous coelacanths from Madagascar|url=https://www.researchgate.net/publication/265667981|journal= Recent Advances in the Origin and Early Radiation of Vertebrates |year=2004|pages= 687–691}}{{cite journal|last1=Dutel|first1=H.|author2=Maisey, J.P.|author3=Schwimmer, D.R.|author4=Janvier, P.|author5=Herbin, M.|author6=Clément, G.|title= The Giant Cretaceous Coelacanth (Actinistia, Sarcopterygii) Megalocoelacanthus dobiei Schwimmer, Stewart & Williams, 1994, and Its Bearing on Latimerioidei Interrelationships|journal=PLOS ONE|year=2012|volume= 7|issue= 11|pages= e49911|doi=10.1371/journal.pone.0049911|pmid= 23209614|pmc= 3507921|bibcode=2012PLoSO...749911D|doi-access=free}} the most recent mawsoniids are Axelrodichthys megadromos from early Campanian to early Maastrichtian freshwater continental deposits of France,{{cite journal|last1=Cavin|first1=L.|author2=Forey, P.L.|author3=Tong, H.|author4=Buffetaut, E.|title=Latest European coelacanth shows Gondwanan affinities|journal=Biology Letters|date=2005|volume=1|issue=2|pages=176–177|doi=10.1098/rsbl.2004.0287|pmid=17148159|pmc=1626220}}{{cite journal|last1=Cavin|first1=L.|author2=Valentin, X.|author3=Garcia, G.|title=A new mawsoniid coelacanth (Actinistia) from the Upper Cretaceous of Southern France|journal=Cretaceous Research|date=2016|volume=62|pages=65–73|doi=10.1016/j.cretres.2016.02.002|bibcode=2016CrRes..62...65C }}{{cite journal|last1=Cavin|first1=L.|author2=Buffetaut, E.|author3=Dutour, Y.|author4=Garcia, G.|author5=Le Loeuff, J.|author6=Méchin, A.|author7=Méchin, P.|author8=Tong, H.|author9=Tortosa, T.|author10=Turini, E.|author11=Valentin, X.|title=The last known freshwater coelacanths: New Late Cretaceous mawsoniids remains (Osteichthyes: Actinistia) from Southern France|journal=PLOS ONE|date=2020|volume=15|issue=6|pages=e0234183|doi=10.1371/journal.pone.0234183|pmc=7274394|pmid=32502171|bibcode=2020PLoSO..1534183C|doi-access=free}} as well as an indeterminate marine mawsoniid from Morocco, dating to the late Maastrichtian{{cite journal|last1=Brito|first1=P.M.|author2=Martill, D.M.|author3=Eaves, I.|author4=Smith, R.E.|author5=Cooper, S.L.A.|year=2021|title=A marine Late Cretaceous (Maastrichtian) coelacanth from North Africa|journal=Cretaceous Research|volume=122|page=104768|doi=10.1016/j.cretres.2021.104768|bibcode=2021CrRes.12204768B |s2cid=233551515|url=https://researchportal.port.ac.uk/portal/en/publications/a-marine-late-cretaceous-maastrichtian-coelacanth-from-north-africa(c8521ebb-5597-4a15-9320-961113ee06d9).html |url-access=subscription}} A small bone fragment from the European Paleocene has been considered the only plausible post-Cretaceous record, but this identification is based on comparative bone histology methods of doubtful reliability.{{cite journal |last1=Ørvig |first1=Tor |title=A vertebrate bone from the Swedish Paleocene |journal=Geologiska Föreningen i Stockholm Förhandlingar |date=1 June 1986 |volume=108 |issue=2 |pages=139–141 |doi=10.1080/11035898609452636 |issn=0016-786X}}

Living coelacanths have been considered "living fossils" based on their supposedly conservative morphology relative to fossil species;{{cite journal |last=Butler |first=Carolyn |title=Living Fossil Fish |journal=National Geographic |date=March 2011 |pages=86–93}}{{rp|1}} however, recent studies have expressed the view that coelacanth morphologic conservatism is a belief not based on data.{{cite journal |doi=10.1002/bies.201200145 |title=Why coelacanths are not 'living fossils' |year=2013 |last1=Casane |first1=Didier |last2=Laurenti |first2=Patrick |journal=BioEssays |volume=35 |issue=4 |pages=332–8 |pmid=23382020|s2cid=2751255 |doi-access=free }} Fossils suggest that coelacanths were most morphologically diverse during the Devonian and Carboniferous, while Mesozoic species are generally morphologically similar to each other.

Cladogram showing the relationships of coelacanth genera after Torino, Soto and Perea, 2021.

{{clade |style=font-size:90%; line-height:90%;

|1=Mimipiscis (Actinopterygii)

|2=Porolepis (Porolepiformes)

|label3=Actinistia

|3={{clade

|1=Miguashaia

|2=Styloichthys

|3=Gavinia

|4={{clade

|1=Diplocercides

|2={{clade

|1=Serenichthys

|2={{clade

|1=Holopterygius

|2=Allenypterus}}

|3={{clade

|1=Lochmocercus

|2={{clade

|1={{clade

|1=Polyosteorhynchus

|2={{clade

|1=Rebellatrix

|2=Hadronector}} }}

|2={{clade

|1=Rhabdoderma

|2={{clade

|1=Caridosuctor

|2={{clade

|1={{clade

|1=Sassenia

|2=Spermatodus}}

|2={{clade

|1={{clade

|1=Piveteauia

|2={{clade

|1=Coccoderma

|2=Laugia}} }}

|2={{clade

|1=Coelacanthus

|2={{clade

|1=Guizhoucoelacanthus

|2={{clade

|1={{clade

|1=Wimania

|2=Axelia}}

|2={{clade

|1=Whiteia

|2={{clade

|1=Heptanema

|2=Dobrogeria

|label3=Latimerioidei

|3={LATIMERIOIDEA}

}} }} }} }} }} }} }} }} }} }} }} }} }} }}

|targetA={LATIMERIOIDEA}

|subcladeA={{clade

|label1=Mawsoniidae

|1={{clade

|1={{clade

|1=Atacamaia

|2=Luopingcoelacanthus

}}

|2={{clade

|1=Yunnancoelacanthus

|2={{clade

|1=Chinlea

|2={{clade

|1=Parnaibaia

|2={{clade

|1=Trachymetopon

|2=Lualabaea

|3={{clade

|1=Axelrodichthys

|2=Mawsonia

}}

}}

}}

}}

}}

}}

|label2=Latimeriidae

|2={{clade

|1=Garnbergia

|2={{clade

|1=Diplurus

|2={{clade

|1={{clade

|1=Megalocoelacanthus

|2=Libys

}}

|2={{clade

|1={{clade

|1=Ticinepomis

|2=Foreyia

}}

|2={{clade

|1=Holophagus

|2={{clade

|1=Undina

|2={{clade

|1=Macropoma

|2={{clade

|1=Swenzia

|2=Latimeria

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}After Ferrante and Cavin (2025):{{clade|{{clade

|label1=Miguashaiidae

|1={{clade

|1=Gavinia

|2=Miguashaia

}}

|2={{clade

|label1=Diplocercidae

|1={{clade

|1={{clade

|1=Ngamugawi

|2={{clade

|1=Diplocercides

|2=Euporosteus

}}

}}

|2={{clade

|1={{clade

|1=Allenypterus

|2=Holopterygius

}}

|2={{clade

|1=Lochmocercus

|2=Serenichthys

}}

}}

}}

|2={{clade

|label1=Hadronectoridae

|1={{clade

|1=Hadronector

|2=Polyosteorhynchus

}}

|2={{clade

|1=Sassenia

|2={{clade

|label1=Rhabdodermatidae

|1={{clade

|1=Spermatodus

|2={{clade

|1=Caridosuctor

|2=Rhabdoderma

}}

}}

|label2=Coelacanthiformes

|2={{clade

|1=Coelacanthus

|2={{clade

|1=Rebellatrix

|2={{clade

|label1=Laugiidae

|1={{clade

|1=Piveteauia

|2={{clade

|1=Coccoderma

|2=Laugia

}}

}}

|2={{clade

|label1=Whiteiidae

|1={{clade

|1=Whiteia

|2={{clade

|1=Garnbergia

|2=Guizhoucoelacanthus

}}

}}

|2={{clade

|label1=Axeliidae

|1={{clade

|1=Atacamaia

|2={{clade

|1=Axelia

|2=Wimania

}}

}}

|label2=Latimerioidei

|2={{clade

|label1=Mawsoniidae

|1={{clade

|1=Indocoelacanthus

|2={{clade

|label1=Diplurinae

|1={{clade

|1=Heptanema

|2={{clade

|1=Diplurus

|2=Reidus

}}

}}

|label2=Mawsoniinae

|2={{clade

|1=Chinlea

|2={{clade

|1=Parnaibaia

|2={{clade

|1=Axelrodichthys

|2={{clade

|1=Mawsonia

|2={{clade

|1=Lualabaea

|2=Trachymetopon

}}

}}

}}

}}

}}

}}

}}

|label2=Latimeriidae

|2={{clade

|1=Dobrogeria

|2={{clade

|label1=Ticinepomiinae

|1={{clade

|1=Ticinepomis

|2={{clade

|1=Foreyia

|2=Rieppelia

}}

}}

|label2=Latimeriinae

|2={{clade

|1=Undina

|2={{clade

|1=Holophagus

|2={{clade

|1={{clade

|1=Latimeria

|2=Swenzia

}}

|2={{clade

|1=Macropoma

|2={{clade

|1=Libys

|2=Megalocoelacanthus

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}

}}|label1=Actinistia|style=font-size:85%; line-height:85%;}}

After Ferrante and Cavin (2025):File:Coelacanth phylogeny.png

File:Latimeria distribution RUS.png

The current coelacanth range is primarily along the eastern African coast, although Latimeria menadoensis was discovered off Indonesia. Coelacanths have been found in the waters of Kenya, Tanzania, Mozambique, South Africa, Madagascar, Comoros and Indonesia. Most Latimeria chalumnae specimens that have been caught have been captured around the islands of Grande Comore and Anjouan in the Comoros Archipelago (Indian Ocean). Though there are cases of L. chalumnae caught elsewhere, amino acid sequencing has shown no big difference between these exceptions and those found around Comore and Anjouan. Even though these few may be considered strays, there are several reports of coelacanths being caught off the coast of Madagascar. This leads scientists to believe that the endemic range of Latimeria chalumnae coelacanths stretches along the eastern coast of Africa from the Comoros Islands, past the western coast of Madagascar to the South African coastline.{{rp|13, 32, 35}} Mitochondrial DNA sequencing of coelacanths caught off the coast of southern Tanzania suggests a divergence of the two populations some 200,000 years ago. This could refute the theory that the Comoros population is the main population while others represent recent offshoots.{{Cite journal|title = Genetically distinct coelacanth population off the northern Tanzanian coast|journal = Proceedings of the National Academy of Sciences|date = 2011-11-01|pmc = 3207662|pmid = 22025696|pages = 18009–18013|volume = 108|issue = 44|doi = 10.1073/pnas.1115675108|first1 = Masato|last1 = Nikaido|first2 = Takeshi|last2 = Sasaki|first3 = J. J.|last3 = Emerson|first4 = Mitsuto|last4 = Aibara|first5 = Semvua I.|last5 = Mzighani|first6 = Yohana L.|last6 = Budeba|first7 = Benjamin P.|last7 = Ngatunga|first8 = Masamitsu|last8 = Iwata|first9 = Yoshitaka|last9 = Abe|bibcode = 2011PNAS..10818009N|doi-access = free}} A live specimen was seen and recorded on video in November 2019 at {{Cvt|69|m}} off the village of Umzumbe on the South Coast of KwaZulu-Natal, {{Cvt|325|km}} south of the iSimangaliso Wetland Park. This is the farthest south since the original discovery, and the second shallowest record after {{Cvt|54|m}} in the Diepgat Canyon. These sightings suggest that they may live shallower than previously thought, at least at the southern end of their range, where colder, better-oxygenated water is available at shallower depths.

The geographical range of the Indonesia coelacanth, Latimeria menadoensis, is believed to be off the coast of Manado Tua Island, Sulawesi, Indonesia, in the Celebes Sea.{{cite journal |last1=Holder |first1=Mark T. |last2=Erdmann |first2=Mark V. |last3=Wilcox |first3=Thomas P. |last4=Caldwell |first4=Roy L. |last5=Hillis |first5=David M. |year=1999 |title=Two Living Species of Coelacanths? |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=96 |issue=22 |pages=12616–20 |bibcode=1999PNAS...9612616H |doi=10.1073/pnas.96.22.12616 |jstor=49396 |pmc=23015 |pmid=10535971 |doi-access=free}} Key components confining coelacanths to these areas are food and temperature restrictions, as well as ecological requirements such as caves and crevices that are well-suited for drift feeding.{{cite journal |bibcode=1988NW.....75..149F |title=Habitat requirements of the living coelacanth Latimeria chalumnae at grande comore, Indian Ocean |last1=Fricke |first1=H. |last2=Plante |first2=R. |volume=75 |year=1988 |pages=149–51 |journal=Naturwissenschaften |doi=10.1007/BF00405310 |issue=3|s2cid=39620387 }} Teams of researchers using submersibles have recorded live sightings of the fish in the Sulawesi Sea as well as in the waters of Biak in Papua.{{cite web |url=http://theconversation.com/hunting-for-living-fossils-in-indonesian-waters-34770 |title=Hunting for living fossils in Indonesian waters|date=30 March 2015 |author=Augy Syaihailatua |work=The Conversation}}{{cite journal |url=http://ir.nrf.ac.za/bitstream/handle/10907/374/Nulens_special_publication3.pdf?sequence=1 |archive-url=https://web.archive.org/web/20180818213827/http://ir.nrf.ac.za/bitstream/handle/10907/374/Nulens_special_publication3.pdf?sequence=1 |url-status=dead |archive-date=18 August 2018 |title=An updated inventory of all known specimens of the coelacanth, Latimeria spp.|author1=Rik Nulens |author2=Lucy Scott |author3=Marc Herbin |journal=Smithiana |date= 22 September 2011|page=2 }}

Anjouan Island and the Grande Comore provide ideal underwater cave habitats for coelacanths. The islands' underwater volcanic slopes, steeply eroded and covered in sand, house a system of caves and crevices which allow coelacanths resting places during the daylight hours. These islands support a large benthic fish population that helps to sustain coelacanth populations.

During the daytime, coelacanths rest in caves anywhere from {{Convert|100 to 500|m|sp=us}} deep. Others migrate to deeper waters.{{rp|37}} The cooler waters (below {{Convert|120|m|sp=us|disp=or}}) reduce the coelacanths' metabolic costs. Drifting toward reefs and night feeding saves vital energy. Resting in caves during the day also saves energy that otherwise would be expended to fight currents.{{cite journal |doi=10.1007/BF02028843 |title=Coelacanth Latimeria chalumnae aggregates in caves: First observations on their resting habitat and social behavior |year=1991 |last1=Fricke |first1=Hans |last2=Schauer |first2=Jürgen |last3=Hissmann |first3=Karen |last4=Kasang |first4=Lutz |last5=Plante |first5=Raphael |journal=Environmental Biology of Fishes |volume=30 |issue=3 |pages=281–6|bibcode=1991EnvBF..30..281F |s2cid=35672220 }}

File:Coelacanth1.JPG, showing the coloration in life]]

Coelacanth locomotion is unique. To move around, they most commonly take advantage of up- or down-wellings of current and drift. Their paired fins stabilize movement through the water. While on the ocean floor, they do not use the paired fins for any kind of movement. Coelacanths generate thrust with their caudal fins for quick starts. Due to the abundance of its fins, the coelacanth has high maneuverability and can orient its body in almost any direction in the water. They have been seen doing headstands as well as swimming belly up. It is thought that the rostral organ helps give the coelacanth electroreception, which aids in movement around obstacles.

Coelacanths are fairly peaceful when encountering others of their kind. They do avoid body contact, however, withdrawing immediately if contact occurs. When approached by foreign potential predators (e.g. a submersible), they show panic flight reactions, suggesting that coelacanths are most likely prey to large deepwater predators. Shark bite marks have been seen on coelacanths; sharks are common in areas inhabited by coelacanths. Electrophoresis testing of 14 coelacanth enzymes shows little genetic diversity between coelacanth populations. Among the fish that have been caught were about equal numbers of males and females.{{rp|38–40}} Population estimates range from 210 individuals per population to 500 per population.{{rp|39}}{{cite journal |doi=10.1111/j.1523-1739.1998.97060.x |jstor=2387536 |title=Population Monitoring of the Coelacanth (Latimeria chalumnae) |year=2008 |last1=Hissmann |first1=Karen |last2=Fricke |first2=Hans |last3=Schauer |first3=Jürgen |journal=Conservation Biology |volume=12 |issue=4 |pages=759–65|s2cid=83504862 }} Because coelacanths have individual color markings, scientists think that they recognize other coelacanths via electric communication.

Coelacanths are nocturnal piscivores that feed mainly on benthic smaller fish and various cephalopods. They are "passive drift feeders", slowly drifting along currents with only minimal self-propulsion, eating whatever prey they encounter. Coelacanths also use their rostral organ for its electroreception to be able to detect nearby prey in low light settings.{{Cite book |last=Bruton |first=Michael |title=The ecology and conservation of the coelacanth Latimeria chalumnae |publisher=Kluwer Academic Publishers |year=1991 |location=Netherlands |pages=313–339 |language=English}}

File:Latimeria chalumnae embryo.jpg]]

File:Coelacanth_egg.jpg

Coelacanths are ovoviviparous, meaning that the female retains the fertilized eggs within her body while the embryos develop during a gestation period of five years. Typically, females are larger than the males; their scales and the skin folds around the cloaca differ. The male coelacanth has no distinct copulatory organs, just a cloaca, which has a urogenital papilla surrounded by erectile caruncles. It is hypothesized that the cloaca everts to serve as a copulatory organ.{{rp|27}}

Coelacanth eggs are large, with only a thin layer of membrane to protect them. Embryos hatch within the female and eventually are born alive, which is a rarity in fish. This was only discovered when the American Museum of Natural History dissected its first coelacanth specimen in 1975 and found it pregnant with five embryos.{{cite web|title = The Coelacanth: Five Fast Facts|url = http://www.amnh.org/explore/news-blogs/from-the-collections-posts/the-coelacanth-five-fast-facts|website = AMNH|access-date = 2015-10-28}} Young coelacanths resemble the adult, the main differences being an external yolk sac, larger eyes relative to body size and a more pronounced downward slope of the body. The juvenile coelacanth's broad yolk sac hangs below the pelvic fins. The scales and fins of the juvenile are completely matured; however, it does lack odontodes, which it gains during maturation.

A study that assessed the paternity of the embryos inside two coelacanth females indicated that each clutch was sired by a single male.{{Cite journal|title = Single-male paternity in coelacanths|journal = Nature Communications|volume = 4|page = 2488|doi = 10.1038/ncomms3488|pmid = 24048316|year = 2013|last1 = Lampert|first1 = Kathrin P.|last2 = Blassmann|first2 = Katrin|last3 = Hissmann|first3 = Karen|last4 = Schauer|first4 = Jürgen|last5 = Shunula|first5 = Peter|last6 = Kharousy|first6 = Zahor el|last7 = Ngatunga|first7 = Benjamin P.|last8 = Fricke|first8 = Hans|last9 = Schartl|first9 = Manfred|bibcode = 2013NatCo...4.2488L|url = http://oceanrep.geomar.de/22046/1/Lampert%20etal_coelacanth-paternity_NatureComms_2013.pdf}} This could mean that females mate monandrously, i.e. with one male only. Polyandry, female mating with multiple males, is common in both plants and animals and can be advantageous (e.g. insurance against mating with an infertile or incompatible mate), but also confers costs (increased risk of infection, danger of falling prey to predators, increased energy input when searching for new males).{{citation needed|date=December 2021}}

Because little is known about the coelacanth, the conservation status is difficult to characterize. According to Fricke et al. (1995), it is important to conserve the species. From 1988 to 1994, Fricke counted some 60 individuals of L. chalumnae on each dive. In 1995 that number dropped to 40. Even though this could be a result of natural population fluctuation, it also could be a result of overfishing. The IUCN currently classifies L. chalumnae as "critically endangered",{{cite iucn |author=Musick, J.A. |date=2000 |title=Latimeria chalumnae |volume=2000 |page=e.T11375A3274618 |doi=10.2305/IUCN.UK.2000.RLTS.T11375A3274618.en |access-date=13 November 2021}} with a total population size of 500 or fewer individuals.{{rp|39}} L. menadoensis is considered Vulnerable, with a significantly larger population size (fewer than 10,000 individuals).{{cite iucn |author=Erdmann, M. |date=2008 |title=Latimeria menadoensis |volume=2008 |page=e.T135484A4129545 |doi=10.2305/IUCN.UK.2008.RLTS.T135484A4129545.en |access-date=13 November 2021}}

The major threat towards the coelacanth is the accidental capture by fishing operations, especially commercial deep-sea trawling.{{cite news |url=https://www.theguardian.com/environment/2006/jan/08/food.fishing |title=Dinosaur fish pushed to the brink by deep-sea trawlers |work=The Observer |date=7 January 2006 |first=Inigo |last=Gilmore}}{{cite web|title = Coelacanth|url = http://www.animalplanet.com/tv-shows/river-monsters/fish-guide/coelacanth/|website = Animal Planet|access-date = 2015-10-29|date = 2012-08-27}} Coelacanths usually are caught when local fishermen are fishing for oilfish. Fishermen sometimes snag a coelacanth instead of an oilfish because they traditionally fish at night, when oilfish (and coelacanths) feed.

Before scientists became interested in coelacanths, they were thrown back into the water if caught. Now that they are recognized as important, fishermen trade them to scientists or other officials. Before the 1980s, this was a problem for coelacanth populations. In the 1980s, international aid gave fiberglass boats to the local fishermen, which moved fishing beyond the coelacanth territories into more productive waters. Since then, most of the motors on the boats failed, forcing the fishermen back into coelacanth territory and putting the species at risk again.{{rp|40}}{{cite journal |bibcode=1995Natur.374..314F |title=Yet more danger for coelacanths |last1=Fricke |first1=Hans |last2=Hissmann |first2=Karen |last3=Schauer |first3=Jürgen |last4=Plante |first4=Raphael |volume=374 |year=1995 |pages=314–5 |journal=Nature |doi=10.1038/374314a0 |pmid= |issue=6520|s2cid=4282105 |doi-access=free }}

Methods to minimize the number of coelacanths caught include moving fishers away from the shore, using different laxatives and malarial salves to reduce the demand for oilfish, using coelacanth models to simulate live specimens, and increasing awareness of the need for conservation. In 1987 the Coelacanth Conservation Council advocated the conservation of coelacanths. The CCC has branches located in Comoros, South Africa, Canada, the United Kingdom, the U.S., Japan, and Germany. The agencies were established to help protect and encourage population growth of coelacanths.{{rp|40}}{{cite web|title = Endangered Species Act Status Review Report for the Coelacanth (Latimeria chalumnae) |url = http://www.nmfs.noaa.gov/pr/species/Status%20Reviews/coelacanth_sr_2014.pdf|archive-url = https://web.archive.org/web/20150907232943/http://www.nmfs.noaa.gov/pr/species/Status%20Reviews/coelacanth_sr_2014.pdf|archive-date = 2015-09-07|website = nmfs.noaa.gov|access-date = 2015-10-30|author=}}

A "deep release kit" was developed in 2014 and distributed by private initiative, consisting of a weighted hook assembly that allows a fisherman to return an accidentally caught coelacanth to deep waters where the hook can be detached once it hits the seafloor. Conclusive reports about the effectiveness of this method are still pending.{{cite web|url=http://www.gpo.gov/fdsys/pkg/FR-2015-03-03/html/2015-04405.htm|title=Proposed Rule To List the Tanzanian DPS of African Coelacanth as Threatened Under the Endangered Species Act|publisher=NOOA (US)|access-date=30 October 2015}}

In 2002, the South African Coelacanth Conservation and Genome Resource Programme was launched to help further the studies and conservation of the coelacanth. This program focuses on biodiversity conservation, evolutionary biology, capacity building, and public understanding. The South African government committed to spending R10 million on the program.{{cite press release |title=South Africa announces plans for Coelacanth Programme |publisher=Science in Africa |date=February 2002 |url=http://scienceinafrica.com/south-africa-announces-plans-coelacanth-programme |access-date=19 April 2013 |archive-date=2 April 2015 |archive-url=https://web.archive.org/web/20150402191757/http://scienceinafrica.com/south-africa-announces-plans-coelacanth-programme |url-status=dead }}{{cite web |title=South African Coelacanth Conservation and Genome Resource Programme |publisher=African Conservation Foundation |url=http://www.wildnetafrica.org/explorer/item/south-african-coelacanth-conservation-and-genome-resource-programme?category_id=2545 |access-date=19 April 2013 |archive-url=https://web.archive.org/web/20150402155421/http://www.wildnetafrica.org/explorer/item/south-african-coelacanth-conservation-and-genome-resource-programme?category_id=2545 |archive-date=2 April 2015 |url-status=dead }} In 2011, a plan was made for a Tanga Coelacanth Marine Park to conserve biodiversity for marine animals including the coelacanth. The park was designed to reduce habitat destruction and improve prey availability for endangered species.

File:Coelacanth sea world.JPG|Coelacanth

File:Coelacanth in Kuwait by Prof Dr Norman Ali Khalaf July 2019.jpg|Coelacanth at Abdallah Al Salem Cultural Center in Kuwait

Coelacanths are considered a poor source of food for humans and likely most other fish-eating animals. Coelacanth flesh has large amounts of oil, urea, wax esters, and other compounds that give the flesh a distinctly unpleasant flavor, make it difficult to digest, and can cause diarrhea. Their scales themselves secrete mucus, which combined with the excessive oil their bodies produce, make coelacanths a slimy food.{{Cite magazine|title = The Creature Feature: 10 Fun Facts About the Coelacanth|url = https://www.wired.com/2015/03/creature-feature-10-fun-facts-coelacanth/|magazine = Wired|access-date = 2015-10-30|date = 2015-03-02}} Where the coelacanth is more common, local fishermen avoid it because of its potential to sicken consumers.{{cite web |url=http://www.straightdope.com/columns/read/3029/know-any-good-recipes-for-endangered-prehistoric-fish-plus |title=Know any good recipes for endangered prehistoric fish? Plus: Do caribou like the Alaska oil pipeline? |publisher=The Straight Dope |first=Cecil |last=Adams |date=30 December 2011}} As a result, the coelacanth has no real commercial value apart from being coveted by museums and private collectors.{{cite book |author-link=Ross Piper |last=Piper |first=Ross |year=2007 |title=Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals |url=https://archive.org/details/extraordinaryani0000pipe |url-access=registration |publisher=Greenwood Press |isbn=978-0-313-33922-6|page=249}}

Because of the surprising nature of the coelacanth's discovery, they have been a frequent source of inspiration in modern artwork, craftsmanship, and literature. At least 22 countries have depicted them on their postage stamps, particularly the Comoros, which has issued 12 different sets of coelacanth stamps. The coelacanth is also depicted on the 1000 Comorian franc banknote, as well as the 5 CF coin.{{cite book | last=Smith | first=J. L. B. | title=The Annotated Old Four legs | publisher=Struik Travel & Heritage | location=Cape Town | year=2017 | isbn=978-1-77584-501-0 | oclc=1100871937 |pages = 322–327}}

In the Pokémon media franchise, the Pokémon known as Relicanth is based on the coelacanth.{{cite journal|first1=Augusto B.|last1=Mendes|first2=Felipe V.|last2=Guimarães|first3=Clara B. P.|last3=Eirado-Silva|first4=Edson P.|last4=Silva|year=2017|title=The ichthyological diversity of Pokémon|url=https://www.researchgate.net/publication/316888282|journal=Journal of Geek Studies|volume=4|issue=1|pages=39–67|access-date=12 July 2019|issn=2359-3024}}{{cite web|url=https://www.discoverwildlife.com/animal-facts/pokemon-characters-real-wild-animals|title=20 Pokémon characters inspired by real wild animals|last=Williams|first=Leoma|date=24 May 2023|publisher=BBC Wildlife|access-date=10 December 2023}}

In the video game series Animal Crossing, the coelacanth is a rare fish that can be caught by the player by fishing in the ocean.{{cite web|url=https://www.popsci.com/story/science/weirdest-thing-animal-crossing-coelacanth-plague-mask-green-blood/|title=Animal Crossing's most elusive fish has a bizarre real-life backstory|date=8 April 2020|work=Popular Science|access-date=10 December 2023}}{{cite web|url=https://www.cbr.com/animal-crossing-rare-fish-guide/|title=Animal Crossing: How to Catch the Game's Rarest Fish|last=Nairn|first=Lacie|date=1 April 2020|website=Comic Book Resources|access-date=10 December 2023}}

{{Reflist|2}}

• {{cite book|last=Bruton|first=Mike|title=When I Was a Fish: Tales of an Ichthyologist|publisher=Jacana Media(Pty)Ltd|year=2015}}
• {{cite magazine|title=Coelacanths – The Fish That Time Forgot|first=Hans|last=Fricke|magazine=National Geographic|pages=824–838|volume=173|issue=6|date=June 1988|issn=0027-9358|oclc=643483454}}
• {{cite journal|last=Sepkoski |first=Jack |title=A compendium of fossil marine animal genera |journal=Bulletins of American Paleontology |volume=364 |page=560 |year=2002 |url=http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=611&rank=class |access-date=2011-05-17 |url-status=dead |archive-url=https://web.archive.org/web/20090220223520/http://strata.ummp.lsa.umich.edu/jack/showgenera.php?taxon=611&rank=class |archive-date=20 February 2009 }}
• {{cite book|last=Thomson|first=Keith S.|title=Living Fossil: the Story of the Coelacanth|publisher=W. W. Norton|year=1991}}
• {{cite news|last=Wade|first=Nicholas|url=https://www.nytimes.com/2013/04/18/science/coelacanth-dna-may-tell-how-fish-learned-to-walk.html|title=Fish's DNA May Explain How Fins Turned to Feet|newspaper=The New York Times|date=18 April 2013|pages=A3}}
• {{cite book|last=Weinberg|first=Samantha|title=A Fish Caught in Time: The Search for the Coelacanth|publisher=Fourth Estate|year=1999}}

{{Commons category|Coelacanthiformes}}

{{Wikispecies|Latimeria}}

• [https://www.pbs.org/wgbh/nova/fish/anatomy.html Anatomy of the coelacanth] by PBS (Adobe Flash required)
• [http://www.dinofish.com/ Dinofish.com] (requires a frame-capable browser)
• {{cite web |first=Carolyn |last=Butler |title=Der Quastenflosser: Ein Fossil taucht auf |trans-title=The Coelacanth: A fossil turns up |language=de |url=http://www.nationalgeographic.de/reportagen/der-quastenflosser-ein-fossil-taucht-auf |work=National Geographic Deutschland |date=August 2012 |access-date=19 April 2013 |archive-date=3 February 2017 |archive-url=https://web.archive.org/web/20170203124532/http://www.nationalgeographic.de/reportagen/der-quastenflosser-ein-fossil-taucht-auf |url-status=dead }}
• [https://www.bbc.co.uk/news/science-environment-22184556 'Living fossil' coelacanth genome sequenced] BBC News Science & Environment; 17 April 2013

{{Sarcopterygii}}

{{Actinistia|state=collapsed}}

{{Diversity of fish}}

{{Evolution of fish|state=collapsed}}

{{Taxonbar|from1=Q59166|from2=Q2637499|from3=Q61881939}}

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Category:Latimeriidae

Category:Live-bearing fish

Category:Ovoviviparous fish

Category:Fish of the Comoros

Category:Fish of Indonesia

Category:Fish of Kenya

Category:Fish of Mozambique

Category:Marine fish of South Africa

Category:Fish of Tanzania

Category:Extant Early Devonian first appearances

Category:1938 in biology